Sample containers may be transported by automated systems in various areas of a laboratory system. Such areas may include input, distribution, centrifuge, decapper, aliquotter, output, sorting, recapping, and secondary tube lift areas. Sample containers may include sample tubes that may contain material for medical analysis, such as blood, serum, gel, plasma, etc. Sample containers may be placed in a rack, tray or sample carrier for storage, processing or for ease of transportation. Racks, trays and sample carriers may also be placed in drawers in specific arrangements to accommodate various workflows or classifications of samples.
Operators of laboratory automation systems can use sample racks to arrange samples in a particular pattern and order to enable the automation equipment to remove samples from these racks based upon their position within the pattern. Likewise, the automation equipment can place samples and sample containers into racks in a particular pattern and order to enable the operator to remove the samples from the racks in a specific pattern and order. If the operator does not orient a rack correctly on the automation equipment, then it is difficult to associate the correct positions within the rack to the sample containers in the rack.
A known solution to overcome the above problem provides loading the racks onto the automation equipment in a unique orientation. A unique feature of the rack can be matched with a mating feature on the automation equipment to accomplish the unique orientation. However, this solution may be frustrating for the operator. It may take multiple attempts for the operator to install the rack onto the automation equipment to obtain the desired orientation.
Another solution, as described by patent application US 2011095864 works for racks having two possible orientations. A square rack having equal length sides could be placed onto the automation equipment in four different orientations. However, with this solution only two out of four possible orientations can be identified. Thus, conventional approaches could be improved.
Embodiments of the invention address these and other problems, individually and collectively.